In his Guterres, he explained the clear breaches and explicit violations that this war represents about what he considered the foundations of international legitimacy, which he interpreted primarily in light of the rules of international law, the principles and purposes of the United Nations Charter, the provisions of international humanitarian law, and the relevant resolutions of the United Nations and particularly those of its Security Council.
Paragraph 4 of Article 2 of the UN Charter prohibits the use of force or the threat of using it. It affirms that member states must refrain in their international relations from threatening to use force or actually using it against the territorial integrity or political independence of any other state, in any manner inconsistent with the purposes of the United Nations.
Article 51 of the UN Charter, however, clarifies that nothing in the Charter impairs the inherent right of any UN member state to exercise its natural right of self-defence, whether individually or collectively, if the state is subjected to an armed attack. This right continues until the UN Security Council takes the necessary measures required to fulfil its responsibility of maintaining international peace and security.
The article also obligates the state that has been attacked and has acted in self-defence to report immediately to the Security Council on the measures it has taken, while ensuring that such actions in no way affect the authority and responsibility of the Security Council, under the UN Charter, to take whatever measures it deems necessary, at any time and to whatever extent it considers appropriate, either to maintain international peace and security or to restore them.
It is clear that Article 51, the only article in the UN Charter that permits and authorizes states to use force, whether individually or collectively, does not apply to the current American-Israeli war against Iran. It is difficult for either of the two states to invoke it to justify launching a war on Iran.
The article requires, for a war to be considered self-defence, that the state launching the war must have actually been subjected to an armed attack, not merely that it anticipates that it be subject to a military attack, or that such an attack is merely possible. This view remains valid even with attempts by some international jurists to broaden the interpretation of Article 51 to include situations of “imminent threat” of armed aggression against a state, which might allow it the right to launch a pre-emptive war against the state that is the source of such a threat.
However, both Israel and the US hold a different view from the one outlined above, in the context of their efforts to internationally legitimize their joint decision to wage war on Iran and their attempt to obtain some degree of acknowledgment, recognition, or at least understanding from the international community that would grant some level of legitimacy to their war on Iran.
For its part, Israel has argued from the very first moment of launching the war on Iran, despite acknowledging that preparations for the war were jointly conducted with the US several months ago and that the date of launching the war had been agreed upon between the two sides weeks ahead, that it launched the war in self-defence.
According to Israeli officials, Iran’s military capabilities under the political system that has ruled Iran since 1979 have continuously constituted a threat to the very existence of Israel and its people, because Iran allegedly seeks the destruction of Israel. Israeli leaders were keen to describe the war as a “pre-emptive war,” aimed at thwarting an Iranian military attack that Tehran was allegedly preparing to launch imminently against Israel.
However, this official Israeli argument does not stand up well to reality. First, the Israeli side has provided no evidence of an imminent threat of war from Iran. Second, Israeli officials had previously stated, after the end of the 12-day war that it waged against Iran in June 2025, that the war, including USA’s participation on its penultimate day, had caused extensive destruction not only to what Washington and Tel Aviv then described as Iran’s nuclear capabilities, but also to a wide range of Iranian military capabilities, both ballistic and otherwise.
Furthermore, Israel’s interpretation of Article 51 of the UN Charter, based essentially on predictions about Iran’s future intentions, does not align with the text of the article, nor with the straightforward reading or the conventional interpretation of it. It also does not even correspond with attempts by some international jurists to broaden its interpretation to include the concept of an “imminent threat” of war rather than an actual armed attack.
Turning to the US, it, too, through statements by its political and military leaders, announced that it launched the war to defend the American people from the Iranian threat, meaning that it also described the war as a pre-emptive military strike.
The US administration’s explanation of the threat it refers to has varied, in an attempt to convince the American public itself or to gain understanding and silence, if not acceptance or support, from the international community.
These explanations have ranged from claims that Iran possesses ballistic missiles capable of reaching the US and striking and destroying targets there, to reminding American citizens and the outside world of actions for which Washington accuses Iran of responsibility, actions that have resulted in the deaths of American citizens or caused damage to US facilities around the world, directly or indirectly, since the victory of the Iranian Revolution in February 1979 and the subsequent rupture in relations between the two countries.
Most recently, the US President announced on 9 March that Iran would have attacked Israel and the whole Middle East within just one week if Washington and Tel Aviv had not launched the war against Iran on 28 February 2026.
As for the claim that the war was pre-emptive, a response came from within Washington itself when intelligence information leaked, or was leaked, to some American media that US security and military agencies had estimated, just before the American-Israeli war on Iran, that Tehran would not complete the development of missiles capable of reaching the United States until 2035.
Although these leaked reports were disputed both inside and outside the US, even if they were assumed to be correct, they would not grant Washington the right to launch a war in February 2026 to prevent something that might occur in 2035.
In this case, the argument that the United States was subjected to an armed attack by Iran, or even that there was an “imminent threat” of such an attack, clearly collapses. Likewise, the justification based on previous Iranian attacks against American targets or individuals does not hold in this context, because none of the cases cited by the US administration would be considered an Iranian military attack against the US in the conventionally understood legal sense. Furthermore, the incidents cited by the American side occurred in the past and therefore do not meet the criteria set out in Article 51 of the UN Charter.
In conclusion, it is important to cite two additional relevant elements regarding the international legitimacy of the “use of force” to further support the argument elaborated in this article.
The first example comes from what the International Court of Justice (ICJ), one of the principal organs of the United Nations, stated when examining the case of “United States of America versus Nicaragua” in 1986. The Court held that an actual armed attack must exist to grant international legitimacy to a war claimed to be in self-defence, and not merely a hypothetical future threat in the minds of the leaders of the state launching the war under the pretext of self-defence.
The second point is that no resolution has been issued by the UN Security Council, under Article 42 of the United Nations Charter, nor by the UN General Assembly under the well-known “Uniting for Peace” resolution, authorizing either the United States, Israel, or both to use force against Iran. Nor has any resolution been adopted that even permits or endorses the use of force in this case.
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